Trapped key interlocking utilizes locks and keys for sequential control of equipment and machinery. Trapped key interlocks are widely used to ensure safe access to potentially live or dangerous plant or equipment in an industrial setting. A safe sequence of operations is enabled through transfer of keys that are either trapped or released in a predetermined order.

A trapped key interlock prevent injury to personnel, protects equipment from damage, and assures continuity of electrical supply by initially restricting any unauthorized access. This is particularly important for HV substations located in remote, unmanned sites. Secondly, they ensure that all authorized access is done in a safe manner, requiring that part of a system is isolated and correctly earthed before maintenance can be carried out on that section.

A well-designed interlocking scheme also ensures that the system is operated correctly. This can prevent a number of dangerous scenarios such as: switching two incoming feeds onto a common bus bar, the paralleling of two energy sources, or disconnecting breakers under load. This greatly reduces the risk of fire or arc flash, further protecting equipment from damage, preventing injury, and avoiding supply interruption.

For HV substation applications, Kirk recommends its HD Series interlocks. The lock housing, cylinder, and inner workings are manufactured entirely of 316 stainless steel. A robust dowel pin key design resists breakage and prevents duplication. A gasketed flip cover protects the keyways from debris. The HD Series range includes mechanical and electromechanical bolt, access, transfer, and valve interlocks, along with a full range of accessories to form a comprehensive switchgear interlocking scheme for HV substations.

Featured Video

ARC Facilities provides you a hassle-free way to centralize and access your building’s critical information. A mobile-friendly dashboard with customized navigation gets you to your O&Ms, drawings, and warranties in seconds, not minutes or hours.

The new $40 million service center at Wisconsin’s Appleton International Airport will create approximately 200 jobs, and add maintenance capacity. - Read: Gulfstream Expansion Creating 200 Jobs In Wisconsin at BusinessFacilities.com.

The global security and aerospace company will invest more than $50 million to expand its Orlando, FL operations. - Read: Lockheed Martin Expanding, Creating 500 Jobs In Florida at BusinessFacilities.com.

Alabama exports totaled a record $21.7 billion last year, thanks in large part to increased overseas shipments of automobiles, aircraft components, chemicals, paper, and minerals. - Read: Alabama’s 2017 Exports Set New Record at BusinessFacilities.com.

E-News Signup

Join 25,000+ Subscribers & Get the latest from Facility Executive!

Facility Executive is your one-stop source for information on quality operation, design and maintenance of facilities. Facility Executive offers a shared community of facility management experts who explore and analyze issues that affect your facility and its environment.

Facility Executive is a specialized trade publication written and edited for corporate facility executives in all industry and service sectors whose responsibilities include purchasing, planning and approving products, services and materials for facility operations.